On June 6th 1944, Dwight D. Eisenhower pulled off the most stunning and impressive invasion in military history. A total of 156,000 Allied troops invaded the beaches of Normandy and by June 11 more than 326,000 troops had crossed with over 100,000 tons of military equipment. One of those men was my grandfather.

Eisenhower’s critics often harped that he was more of an organizer than a leader. But it was in the days after D-Day that Eisenhower illustrated one of the most profound and clear moments of leadership — an example that entrepreneurs can follow.

After their hard-won initial successes, the Allied troops became bogged down in the hedgerows of France. These obstacles — half earth, half hedge, sometimes 15 feet tall — plus the reality of coordinating that many men and so much material created a temporary stall, allowing the Germans to wage a series of counteroffensives — a final blitzkrieg of some 200,000 men.

The German blitzkrieg was one of the most intimidating and shocking developments in modern warfare. At the beginning of World War II, columns of Panzer tanks rushed into Poland, the Netherlands, Belgium and France with devastating results and little opposition. In most cases, the commanders confronted by the Germans simply surrendered rather than face what felt to them like an invincible, indefatigable monster bearing down.

The blitzkrieg strategy was designed to exploit the flinch. The Allied forces would collapse at the sight of what appeared to be overwhelming force. Its success depended completely on such a response. The military strategy worked because the set-upon troops saw the offensive force as an enormous obstacle.

That was reaction of the Allied forces to the blitzkrieg for most of the war. They could see only its power and their vulnerability. How could they stop it? And when that final blitzkrieg came, would it throw them back to the very beaches they had just purchased at such high cost?

Eisenhower answered that question unequivocally. Striding into a hastily assembled conference room at the Malta headquarters, the American general made an announcement: He would have no more of this quivering timidity. “The present situation is to be regarded as opportunity for us and not disaster,” he said. “There will be only cheerful faces at this conference table.”

Eisenhower was able to see a tactical solution that had been there the entire time: The Nazi strategy carried its own destruction.

Finally, the Allies were able see the opportunity inside the obstacle rather than simply an obstacle threatening them. As long as the Allies could bend and not break, more than 50,00 Germans could be sent rushing headfirst into a net — or a “meat grinder,” as General George Patton eloquently put it.

The Battle of the Bulge and the previous Battle of the Falaise Pocket — which the Allies initially feared were major reversals and the end of their momentum — set the stage for stunning triumphs. By allowing a forward wedge of the German army to pass through and then attacking from the sides, the Allies encircled the enemy completely from the rear. The invincible, penetrating thrust of the German Panzers became not just impotent but suicidal — a textbook example of why flanks should never be left exposed.

Eisenhower’s important decision is a moment I think of often. My grandfather, who landed at Normandy two days after D-Day, experienced these initial setbacks only to later fight at Battle of the Bulge, which resulted in his being awarded the French Croix de Guerre. Eisenhower’s decision reminds me of the role that perceptions play in the success or failures of those in opposition.

It’s one thing to not be overwhelmed by obstacles — to not become discouraged or upset. Few people can do this. But only after controlling one’s emotions, seeing objectively and standing steadily does the next step becomes possible: a mental flip, to look not at the obstacle but at the opportunity within.

As Laura Ingalls Wilder put it, “There is good in everything, if only we look for it.”

Yet many people close their eyes to the gift. Imagine being in Eisenhower’s shoes, with an army racing closer and only impending defeat seemingly in view. How much longer would the war continue? How many more lives would be lost?

Or imagine being Thomas Edison when his entire research and production facility became consumed in a terrible fire? Instead of feeling heartbroken, Edison calmly but quickly proceeded to the fire. “Go get your mother and all her friends,” he told his son. “They’ll never see a fire like this again.”

The hard thing about hard things is that people often make them worse by seeing the disaster and not the opportunity presented. The danger lies in assuming that things need to be a certain way. Businesspeople assume that they’re at a disadvantage or that it would be a waste of time to pursue an alternate course. In reality it’s all fair game and every situation is an opportunity to act.

Blessings and burdens are not mutually exclusive. It’s a lot more complicated.

Try to remember, in moments like these, that a second act comes along with these unfortunate situations.

Sports psychologists recently did a study of elite athletes caught up with adversity or serious injury. Initially, each reported having a sense of isolation, emotional disruption and doubts about their athletic ability. Yet afterward, they reported having a desire to help others, added perspective and a realization of their strengths. The fear and doubt encountered during the injury turned into their realization of greater abilities.

It’s a beautiful idea. Psychologists call it adversarial and post-traumatic growth. “That which doesn’t kill me makes me stronger” is not a cliché but fact.

The struggle against an obstacle inevitably propels the fighter to a new level of functioning. The extent of the struggle determines the extent of the growth. The obstacle is an advantage, not adversity.

So this is what can be learned from Eisenhower about any situation bearing down right now. Be the one to stride into the conference room and make it clear: This will be an opportunity and not disaster. Be the first cheerful face at the conference table.